Recently, several products have been introduced claiming the ergonomic benefits of angled handles. Such bent handles add leverage and reduce joint stress through enhanced alignment of tool shaft with user's arm. While user comments have been encouraging, sales have been less than impressive, suggesting a less than sufficient ergonomic advantage to the public at large. Still, there is a growing concern over repetitive motion injuries in industry, an ever present need to modernize production and introduce ergonomic advantages to new technologies, as well as an interest in the marketing value of new designs. Each of these factors add to the demand for more satisfying and effective tool handles. Thus, the generative "ergonomic" challenge persists--to make handles that are safer and easier to use, while being attractive and cost competitive.
One of the basic goals of ergonomic tool design is to determine a handle shape which can reduce discomfort and improve performance, through proper fit. Therefore, comprehensible criteria for handle specifications are sought, to translate the subjective construct of "proper fit" into relatively more clear-cut engineering terms. In sum, this tool handle innovation represents a simple rule for manufacture, in order to create an "ergonomic" tool handle. The premise of this invention is that, tool handles, with a certain angular configuration, will substantially reduce problems of user discomfort, and increase tool use effectiveness, at a worthwhile cost of manufacture.
The handle, in this invention, is specially designed to acknowledge the natural angles between the gripping portion of the hand, the axis of the forearm, and their alignment with the torso, during use. This tool handle configuration tries to conform with a certain anatomical posture, emphasizing a relatively straight, balanced, and relaxed alignment of the wrist, arm and torso. This certain posture describes a pointing-type hand grip, a straight wrist, and a partially bent elbow more or less close to a generally erect torso. The maintenance of this posture improves the likelihood of tool control and comfort during work performance. The handle, in this invention, allows the user to execute work activities, from this certain posture, more often than conventional prior art handles. The resultant benefits from such an advantage are substantial.